Chmod 600 Explained & Calculator
Learn why chmod 600 protects private keys and secret files, inspect every permission, and copy the correct command.
STEP 1
What are you changing?
Execute means different things for a file and a directory.
STEP 2
Choose access
YOUR RESULT
rw-------u=rw,g=,o=
Owner
Can read, edit
Group
Can no access
Everyone else
Can no access
THE PART MOST CALCULATORS SKIP
See what will actually change
Find the numeric mode with stat -c '%a' path on Linux, then review each permission being added or removed.
TOP 5 EVERYDAY MODES
Start from the job, not the digits
Each common mode has its own explainer page and loads directly into this calculator. Pick the situation that sounds like yours, then check the access before copying.
755Public directory or script
You control it; everyone else can open or run it.
644Regular file
You can edit it; everyone else can read it.
600Private or secret file
Only you can read or edit it.
700Private directory or script
Only you can open, change, or run it.
775Team directory
You and your group can edit; everyone else can browse.
CHMOD IN ONE MINUTE
What is chmod?
Every Linux file carries a tiny access list. chmod is the command that rewrites that list. It does not move the file, change its contents, or choose its owner—it only changes what the owner, group, and everyone else are allowed to do.
Think of the three digits as three keycards. The first card belongs to the owner, the second to the group, and the third to everyone else. Each card gets points for Read (4), Write (2), and Execute (1). Add the allowed actions to get that card's digit.
The only math you need
DIGIT 1 · u
Owner
Usually you or the account that created it.
DIGIT 2 · g
Group
Accounts collected in the file's owning group.
DIGIT 3 · o
Everyone else
Any other account on the same system.